Abstract:The difference of the key indicators between detecting fermented and blended soy sauce was ex－ plored. After very simple preparation， the samples were tested by High Performance Liquid Chromatography （HPLC）. The content of the various organic acids such as formic acid，acetic acid，lactic acid，tartaric acid，cit－ ric acid，succinic acid， pyruvic acid and levulinic acid in the samples were separated very good by HPLC. The results showed that the correlation coefficients were more than 0.997 6， the relative standard deviations are 0.68 %- 5.13 %， the recoveries were 90.6 %-98.2 %，the lowest detection limit were 0.000 1 mg/mL-0.000 5 mg/mL. The soy sauce were produced by different process， there was a big difference in their organic acids content. The HPLC method was simple and accurate. The soy sauce could be well classified by the HPLC method.